Webber was erroneously given the signal to leave the pits after his first stop, despite the right rear not being secured. The wheel immediately detached and rolled down the pit lane.

It narrowly missed some Lotus mechanics and headed into the Mercedes pit, where two FOM TV pit lane cameramen were stationed.

The first was crouching down and facing Webber, and having seen the wheel, he jumped out of the way, leaving his camera on the pit road. The wheel continued move along at ground level -- until it struck the abandoned camera.

It then bounced upwards, hitting Allen -- who was facing the other way after panning around to get Webber's exit -- squarely in the back. He was knocked to the ground, suffering broken ribs and a broken collarbone.

Red Bull initially thought that the man struck was a Mercedes mechanic, but the team was later informed that he was an FOM crew member, and kept informed of his condition.

“Obviously we need to fully understand what's happened and why the wheel wasn't located,” said Horner. “The wheel had obviously detached itself from the car with quite a bit of energy, and knocked a cameraman, Paul Allen, over. Most importantly he's fundamentally OK. Obviously that was our primary concern, but it's a timely reminder that the pit lane is still a pretty dangerous place to be.

“It's a horrible feeling, because your immediate concern is for that individual, that he'll be alright. Initially I thought it was a Mercedes mechanic, but very quickly I was updated by FOM that it was one of their cameramen, and he was on his way to hospital.

“All the initial signs looked OK and they kept me updated during the race with what their findings were. The important thing is that he's OK. It must be shocking for his family as well to see something like that. The most important thing is he's fundamentally OK.”

Regarding Webber, he said, "We chose not to inform Mark at that point, we didn't see that it was relevant for him to be racing with that on his mind, so he was informed after the race. He was obviously very concerned for the wellbeing of the camera guy and pleased to hear that was OK.”

Horner said perhaps people working in the pit lane should be better protected.

“The mechanics have to wear safety gear and helmets, and maybe it's time that we look at perhaps some of the other operational working people having to have some safety equipment as well.

“Head injuries in particular are pretty nasty, so maybe it's something that needs to be looked at.”